Computer Science
Scientific paper
Oct 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994icar..111..289p&link_type=abstract
Icarus (ISSN 0019-1035), vol. 111, no. 2, p. 289-304
Computer Science
79
Abundance, Atmospheric Models, Carbon Dioxide, Evolution (Development), Mars (Planet), Mars Atmosphere, Nitrogen, Radiogenic Materials, Rare Gases, Chronology, Fractionation, Hydrodynamics, Models, Outgassing, Photochemical Reactions, Sputtering
Scientific paper
Carbon dioxide, nitrogen, and the nonradiogenic and radiogenic noble gases are tracked from primordial inventories to their present states in a revised model of atmospheric evolution on Mars. Elemental and isotopic abundances evolve by hydrodynamic escape, impact erosion, outgassing, sputtering, photochemical escape of nitrogen, and carbonate formation and recycling. Atmospheric history is divided into early and late evolutionary periods, the first characterized by high CO2 pressures and a possible greenhouse and the second by a low pressure cap-regolith buffered system initiated by polar CO2 condensation approximately 3.7 Gyr ago. During early evolution the Xe isotopes are fractionated to their present composition by hydraulic escape, and CO2 pressure and isotopic history are dictated by the interplay of losses to erosion, sputtering, and carbonate precipitation, additions by outgassing and carbonate recycling, and perhaps also by feedback stabilization under greenhouse conditions. Atmospheric collapse near 3.7 Gyr leads to abrupt increases in the mixing ratios of preexisting Ar, Ne, and N2 at the exobase and their rapid removal by sputtering. Current abundances and isotopic compositions of these light species are therefore entirely determined by the action of sputtering and photochemical escape on gases supplied by outgassing during the late evolutionary epoch. The present atmospheric Kr inventory also derives almost completely from solar-like Kr degassed during this period. Consequently, among current observables, only the Xe isotopes and delta(C-13) survive as isotopic tracers of atmospheric history prior to its transition to low pressure.
No associations
LandOfFree
Evolution of the martian atmosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolution of the martian atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of the martian atmosphere will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1071461